What was frightening about Gacy's case, as explored in Devil in Disguise, is how a serial killer existed in plain sight in society, attending church and considered civil. A seemingly ordinary man attending birthday parties as a clown for charity turned out to be a psychotic Killer clown with a history of killing more than 30 young men and boys.
The disappearance of young boys was prevalent during the 1900s in Des Plaines, Illinois, a suburb of Chicago. By December 1978, police were investigating yet another disappearance of a 15-year-old, Robert Piest. The investigators discovered he had last gone to Gacy's house to discuss the possibility of a construction job. This is how the cops started to trace Gacy, and what followed next only escalated their suspicion, making it more believable.
Read on to know more.
Devil in Disguise: How did John Wayne Gacy get caught?

As mentioned, it was while investigating the case of Robert Piest's disappearance that Gacy's name came to light. Gacy was a contractor, and Robert was seen visiting Gacy's house to learn about the potential opportunity for any construction job. This very information led the officials to chase Gacy for some time before issuing a search warrant for his home in Des Plaines, Illinois.
During this search, the officials found some suspicious items such as syringes, various kinds of drugs, and belongings and personal documents of other people. Gacy was arrested initially on a minor drug charge from McDonald’s in Niles, Illinois, while the officials dug the case deeper.
Police officials learn about Gacy's secret crawl space in the house, as shown in Devil in Disguise.
They interviewed some young men who had accused Gacy of s*xual assault for more details. Some men mentioned a basement like "crawl space", basically an unfinished area between the ground and the first floor, usually used for access to wiring and plumbing pipes. These men also mentioned digging trenches and spreading lime in the crawl space, and this is what hinted to the officials that Gacy might be hiding bodies in the area.
This is when the officials obtained a second search warrant and searched the crawl space in the house. They found the bodies of around 26 victims in the space, while three additional bodies were found in another property of his. Four bodies, including one of Robert Piest, were discovered in the Des Plaines River.
John Wayne Gacy's trial and conviction
Gacy's trial concluded in 1980, and he was convicted of 33 murders, receiving a death sentence. His death order was carried out by a lethal injection in 1994 after numerous appeals on May 10 in Stateville Correctional Centre, Illinois, at the age of 52 years.
By the end of the last trial, Gacy's legal attorney took the last chance to reduce some of his counts by stating he was insane and a person with different personalities. However, the court didn't buy the same and convicted him, in Devil in Disguise.
In his final statement, as shown in Devil in Disguise, Gacy proclaimed his innocence in his final words, maintaining that he did not commit the murders despite overwhelming evidence and conviction.